Saliva urea nitrogen dipsticks to predict acute kidney injury in Malawian trauma patients

Background: Many low-resource settings have limited access to serum creatinine tests necessary for kidney disease identification. Among Malawian patients who are hospitalized after trauma, we evaluated the use of point-of-care saliva urea nitrogen (SUN) dipsticks to predict acute kidney injury (AKI). Methods: In a nested prospective cohort study, we enrolled hospitalized acute trauma patients aged ≥6 months to evaluate AKI (defined by KDIGO criteria) and the test characteristics of SUN to predict AKI. Results: Among 335 participants (approximately three-quarters able to expectorate and 34% aged ≤18 years), 12.5% (n = 42) developed AKI. At a SUN threshold of ≥40 mg/dL, a positive dipstick test was specific (99.3%) but insensitive (14.3%) in predicting AKI, with a positive predictive value of 75% and negative predictive value of 89%. At this threshold, 2.4% of participants were dipstick-positive (SUN+), and 75% of those had AKI. Reducing the SUN threshold to ≥30 mg/dL increased participants who were SUN+ to 5.0% (n = 16) but also increased the false positive rate and missed 79% (n = 33) of AKI cases. Stratified results showed better performance among adults than children and similar results when comparing participants who could and could not expectorate. There was moderate correlation between categorized BUN values and SUN (r = 0.53) but less agreement (weighted kappa 0.27; 95% CI 0.17–0.37). Conclusions: SUN dipstick testing has good specificity and negative predictive value for ruling out AKI, but poor sensitivity. We found similar results among those who could or could not expectorate a saliva sample

High risk of acute kidney injury in Malawian trauma patients: a prospective observational cohort study

Background: Trauma is a common cause of acute kidney injury (AKI). Yet little data exist regarding trauma-related-AKI in low-resourced settings, where the majority of deaths from AKI and trauma occur. We prospectively evaluated epidemiology of AKI in hospitalized Malawian trauma patients. Methods: AKI was defined by creatinine-only Kidney Disease Improving Global Outcomes (KDIGO) criteria. Those with AKI were followed up 3–6 months later to determine persistent kidney abnormalities. We calculated univariate statistics with Wilcoxon rank sum tests, Fisher’s exact, and chi-square tests to compare those with and without AKI. Multivariate log-risk regression modelling was used to determine risk ratios (RR) and 95% confidence intervals (CI) for AKI development. Results: Of 223 participants, 14.4% (n = 32) developed AKI. Most patients were young (median age 32) males (n = 193, 86.5%) involved in road traffic injuries (n = 120, 53.8%). After adjusting for confounders, those with severe anemia during their admission were 1.4 times (RR 1.4, 95% CI 1.1–1.8) more likely to develop AKI than those without. Overall mortality was 7.6% (n = 17), and those who developed AKI were more likely to die than those who did not (18.8% vs 5.6%, p-value = 0.02). Almost half of those with AKI (n = 32) either died (n = 6) or had persistent kidney dysfunction at follow-up (n = 8). Conclusion: In one of the few African studies on trauma-related AKI, we found a high incidence of AKI (14.4%) in Malawian trauma patients with associated poor outcomes. Given AKI’s association with increased mortality and potential ramifications on long-term morbidity, urgent attention is needed to improve AKI-related outcomes

Incidence and epidemiology of acute kidney injury in a pediatric Malawian trauma cohort: A prospective observational study

Background: Acute kidney injury (AKI) is highly associated with mortality risk in children worldwide. Trauma can lead to AKI and is a leading cause of pediatric death in Africa. However, there is no information regarding the epidemiology of pediatric, trauma-associated AKI in Africa. Methods: Prospective cohort study of pediatric trauma patients admitted to a tertiary referral hospital in Malawi. Participants enrolled at admission were followed prospectively throughout their hospitalization. AKI was defined by creatinine-only Kidney Disease Improving Global Outcomes criteria. We calculated descriptive statistics and univariate relative risks (RR) for hypothesis-generation of potential risk factors associated with AKI. Results: We analyzed data from 114 participants. Depending on baseline creatinine definition, AKI incidence ranged from 4 to 10%. The new Schwartz equation estimated baseline creatinine values best and yielded an AKI incidence of 9.7%. Almost one in ten children died during hospitalization, but those with AKI (n = 4) were at significantly higher risk of death compared to those without AKI (40.0% vs 6.2%; RR 6.5, 95% CI 2.2-19.1). Burn injuries were most commonly associated with AKI (63.6%). Other potential AKI risk factors included multiple injuries, trunk or facial injuries, and recent consumption of herbal remedies. Conclusions: AKI occurs in up to 10% of admitted pediatric trauma patients in Malawi and increases the risk of death 7-fold compared to those without AKI. This large unrecognized burden in trauma requires further investment by researchers, clinicians and policymakers to develop evidenced-based triage, recognition, and management approaches to prevent the associated sequelae and potential mortality from AKI

Validity of Urine NGALds Dipstick for Acute Kidney Injury in a Malawian Trauma Cohort

Introduction: Acute kidney injury (AKI) is a major cause of mortality worldwide, particularly in low-resource settings with limited diagnostic testing. Neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in predicting AKI. Nested within a larger, prospective cohort study evaluating AKI incidence in admitted trauma patients, our objective was to evaluate a novel dipstick, NGALds, for the prediction of AKI in Malawi, Africa. Methods: Participants were >6 months of age. Spearman rank correlation coefficients (R) assessed NGAL categories (negative [≤50 ng/ml], low risk [51−149 ng/ml], moderate risk [150−299 ng/ml], and high risk [≥300 ng/ml]) for the urine NGALds dipstick and laboratory-based NGAL Test. Results: We enrolled 285 participants (one-third children). Thirteen percent developed AKI. The dipstick captured 45 of 52 participants (86.5%) with moderate- or high-risk NGAL values on laboratory-based testing (R = 0.74). The dipstick had sensitivity of 44.4%, specificity of 73.5%, positive predictive value of 19.5%, and negative predictive value of 90.2% for predicting AKI. Acute kidney injury was associated with an increased risk of mortality (relative risk [RR] = 3.9, 95% confidence interval [CI] = 1.9−8.2), but mortality risk greatly increased among children who first had a positive (≥150 ng/ml) NGALds result (RR = 12.0, 95% CI = 1.8−78.4). Conclusions: The NGALds dipstick performed similarly to the NGAL Test in this low-resource setting and may be a useful tool to rule out AKI. It may be even more important in predicting high mortality risk among children